We analyze how the magnetic disorder affects the properties of the two-band s ± and s ++ models, which are the subject of discussions regarding iron-based superconductors and other multiband systems like MgB 2 . We show that there are several cases when the transition temperature T c is not fully suppressed by magnetic impurities in contrast to the Abrikosov-Gor'kov theory, but a saturation of T c takes place in the regime of strong disorder. These cases are: (1) the purely interband impurity scattering and (2) the unitary scattering limit. We show that in the former case the s ± gap is preserved, while the s ++ state transforms into the s ± state with increasing magnetic disorder. For case (2), the gap structure remains intact.
|Journal||Physical review B: Condensed matter and materials physics|
|Publication status||Published - 2014|